Preliminary work on resuming downloads whose connections have expired.

chrome/browser/download/download_manager.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // The DownloadManager object manages the process of downloading, including
 // updates to the history system and providing the information for displaying
 // the downloads view in the Destinations tab. There is one DownloadManager per
 // active profile in Chrome.
 //
 // Download observers:
@@ skipping 92 matching lines @@
   // everything.
   void SearchDownloads(const string16& query,
                        std::vector<DownloadItem*>* result);
 
   // Returns true if initialized properly.
   bool Init(Profile* profile);
 
   // Notifications sent from the download thread to the UI thread
   void StartDownload(DownloadCreateInfo* info);
   void UpdateDownload(int32 download_id, int64 size);
+  void OnResponseCompleted(int32 download_id, int64 size, int os_error);
   void OnAllDataSaved(int32 download_id, int64 size);
+  void DownloadError(int32 download_id, int64 size, int os_error);
 
   // Called from a view when a user clicks a UI button or link.
   void DownloadCancelled(int32 download_id);
   void PauseDownload(int32 download_id, bool pause);
+  void RestartDownload(int32 download_id);
   void RemoveDownload(int64 download_handle);
 
   // Called when the download is renamed to its final name.
   void DownloadRenamedToFinalName(int download_id, const FilePath& full_path);
 
   // Remove downloads after remove_begin (inclusive) and before remove_end
   // (exclusive). You may pass in null Time values to do an unbounded delete
   // in either direction.
   int RemoveDownloadsBetween(const base::Time remove_begin,
                              const base::Time remove_end);
@@ skipping 141 matching lines @@
   // the change to the history system.
   void RenameDownload(DownloadItem* download, const FilePath& new_path);
 
   // Makes the ResourceDispatcherHost pause/un-pause a download request.
   // Called on the IO thread.
   void PauseDownloadRequest(ResourceDispatcherHost* rdh,
                             int render_process_id,
                             int request_id,
                             bool pause);
 
+  // Makes the ResourceDispatcherHost restart a download request.
+  // Called on the IO thread.
+  void RestartDownloadRequest(ResourceDispatcherHost* rdh,
+                              int render_process_id,
+                              int request_id,
+                              DownloadCreateInfo* info);
+
   // Inform observers that the model has changed.
   void NotifyModelChanged();
 
   DownloadItem* GetDownloadItem(int id);
 
   // 'downloads_' is map of all downloads in this profile. The key is the handle
   // returned by the history system, which is unique across sessions. This map
   // owns all the DownloadItems once they have been created in the history
   // system.
   //
@@ skipping 57 matching lines @@
   // The "Save As" dialog box used to ask the user where a file should be
   // saved.
   scoped_refptr<SelectFileDialog> select_file_dialog_;
 
   scoped_ptr<OtherDownloadManagerObserver> other_download_manager_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadManager);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_H_